Age and Social History Impact Social Interactions between Bull Asian Elephants (Elephas maximus) at Denver Zoo

Wild bull Asian elephants spend time in all-male groups. Therefore, managers of ex situ populations increasingly house bulls together. We examined the social interactions five at Denver Zoo, using instantaneous sampling to compare across adolescent and mature bulls, with a history prior integration this group compared no history. Both age significantly affected behavior. Adolescent exhibited more affiliative submissive behaviors when housed mixed-age partners only adolescents, less non-contact agonistic behavior proximity conspecific groups other adolescents. Mature they were increased contact least one bulls. Bulls new engaged affiliative, agonistic, behaviors, spent proximity, than previously established combinations. As institutions socially, our results provide insights into factors that may affect interactions.